Articles | Volume 8, issue 10
Atmos. Chem. Phys., 8, 2763–2771, 2008
Atmos. Chem. Phys., 8, 2763–2771, 2008

  23 May 2008

23 May 2008

Estimation of Asian dust aerosol effect on cloud radiation forcing using Fu-Liou radiative model and CERES measurements

Jing Su1, Jianping Huang1, Qiang Fu1,2, P. Minnis3, Jinming Ge1, and Jianrong Bi1 Jing Su et al.
  • 1College of Atmospheric Science, Lanzhou University, Lanzhou, 730000, People's Republic of China
  • 2Department of Atmospheric Science, University of Washington, Seattle, WA, 98195, USA
  • 3NASA Langley Research Center, Hampton, VA, 23666, USA

Abstract. The impact of Asian dust on cloud radiative forcing during 2003–2006 is studied by using the Clouds and Earth's Radiant Energy Budget Scanner (CERES) data and the Fu-Liou radiative transfer model. Analysis of satellite data shows that the dust aerosol significantly reduced the cloud cooling effect at TOA. In dust contaminated cloudy regions, the 4-year mean values of the instantaneous shortwave, longwave and net cloud radiative forcing are −138.9, 69.1, and −69.7 Wm−2, which are 57.0, 74.2, and 46.3%, respectively, of the corresponding values in pristine cloudy regions. The satellite-retrieved cloud properties are significantly different in the dusty regions and can influence the radiative forcing indirectly. The contributions to the cloud radiation forcing by the dust direct, indirect and semi-direct effects are estimated using combined satellite observations and Fu-Liou model simulation. The 4-year mean value of combination of dust indirect and semi-direct shortwave radiative forcing (SWRF) is 82.2 Wm−2, which is 78.4% of the total dust effect. The dust direct effect is only 22.7 Wm−2, which is 21.6% of the total effect. Because both first and second indirect effects enhance cloud cooling, the aerosol-induced cloud warming is mainly the result of the semi-direct effect of dust.

Final-revised paper